1. Field of the Invention
The present invention relates to a thin absorbent article such as vaginal discharge absorbing sheet called panty liner, urine absorbing sheet for a patient suffering from urinary incontinence, absorbing sheet for receiving a small amount of menstrual blood, or the like.
2. Description of the Related Art
Thin absorbent articles such as panty liner are worn by adhering and fixing onto an inner side of a crotch portion of an undergarment through a pressure sensitive adhesive.
FIG. 6 is a sectional view showing a conventional, commonly used thin absorbent article 1.
In the absorbent article 1, a single- or two-layer intermediate layer 3 is disposed on a backsheet 2 formed of synthetic resin film and having a liquid barrier effect, and a topsheet 4 formed of hydrophilic nonwoven fabric is laid thereon. Along the periphery of the absorbent article 1, there is formed a round-sealed portion 5 where the backsheet 2, intermediate layer 3 and topsheet 4 are thermal bonded. On the garment surface of the backsheet 2, on the other hand, there is provided a pressure sensitive adhesive layer 6 for adhering and fixing to an inner side of a crotch portion of an undergarment.
When the thin absorbent article 1 is adapted for use as panty liner or the like, the topsheet 4 is formed of spunlaced nonwoven fabric comprising hydrophilic fibers such as rayon, and the intermediate layer 3 is formed of a bundle of hydrophobic fibers or water-repellent nonwoven fabric. The absorbent article 1 of this kind aims at receiving a minute amount of body waste or discharged liquid such as vaginal discharge, and is made extremely thin so as to feel integrated with the crotch portion of the undergarment. To this end, the body waste or discharged liquid is absorbed mainly by the hydrophilic topsheet 4, but the intermediate layer 3, which is hydrophobic or water-repellent having no liquid absorbing function, functions as a cushion layer for improving contact feel with the skin of a wearer.
The thin absorbent article 1 of this kind is, for instance, used for locally absorbing and retaining a vaginal discharge or the like discharged from a vaginal opening of a female. In this case, the vaginal discharge or the like is given to the central region of the absorbent article 1 in a concentrated manner and absorbed and retained by the topsheet 4. However, since the conventional absorbent article absorbs the liquid only with the thin topsheet 4, when worn for a long time, the locally applied liquid is easily saturated and left on the surface of the topsheet 4 to give an unpleasant feel to a wearer. As vaginal discharge absorbing sheets, moreover, there has been known a long-size type having an entire length of equal to or larger than 160 mm. However, since it can absorb the liquid only locally with the topsheet 4, the long topsheet 4 can not be effectively utilized, so that the locally applied liquid is liable to provide an unpleasant feel.
In addition since the liquid is absorbed only with the topsheet 4 in the prior art, the liquid absorption speed is low. Therefore, if it is, for instance, used as a pad for a patient suffering from mild urinary incontinence and a relatively large amount of liquid is given thereto, such liquid cannot be absorbed in a short period of time, readily causing lateral liquid leakage from the absorbent article 1.
Of course, if a thick absorbent layer mainly comprising pulp or the like is provided between the backsheet and the topsheet as in sanitary napkins and disposable diapers, the liquid absorption capacity can be increased. However, the absorbent article 1 of this kind must be thin so as to feel integrated with a crotch portion of an undergarment upon wearing, and its thickness is required to be equal to or smaller than 3 mm, preferably equal to or smaller than 2 mm, for instance. Accordingly, it is impossible to provide such thick absorbent layer.
It is also conceivable to provide an extremely thin absorbent layer such as a stack of tissue paper or airlaid pulp between the backsheet and the topsheet. However, since the vaginal discharge or the like is locally given to the topsheet in a concentrated manner, it is impossible to increase the absorption capacity of the locally applied liquid only by providing such thin absorbent layer, so that it is impossible to wear it for a long time.